Plant cytochrome p450

ABSTRACT

This disclosure relates to the isolation and sequencing of nucleic acid molecules that encode cytochrome P450 polypeptides from a  Papaver somniferum  cultivar; uses in the production of noscapine and identification of poppy cultivars that include genes that comprise said nucleic acid molecules.

INTRODUCTION

This disclosure relates to the isolation and sequencing of nucleic acidmolecules that encode novel cytochrome P450s from a Papaver somniferumcultivar, [poppy plant]; transgenic cells transformed with said nucleicacid molecules, sequence variants of the gene; the use of saidgenes/proteins in the production of noscapine and the use of the genesas a marker of poppy plants that synthesize noscapine.

BACKGROUND

Plant cytochrome P450s are a very large family of enzymes responsiblefor the oxidation, peroxidation and reduction of a vast number of plantintermediate metabolites such as alkaloids, terpenoids, lipids,glycosides and glucosinolates. P450s are known to be involved in themetabolism and detoxification of pesticides as well as the biosynthesisof primary and secondary metabolites.

Plant cytochrome P450s are known in the art and have been successfullycloned, expressed and characterized. For example, WO2009/064771 andWO2008/070274, each disclose cytochrome P450 genes and their use in thealteration of alkaloid content in Nicotiana tabacum. These patentapplications describe how the inhibition of specific P450s reduces theamount of N′ nitrosonornicotine, a known carcinogen, in planta.WO2008/150473 discloses the over expression of cytochrome P450s toconfer resistance or tolerance to herbicides, in particular,benzothiadiazones and sulfonylureas. In WO2008/088161 is disclosedtransgenic plants that over express a cytochrome P450 which results inincreased seed size or the storage protein content of seeds. The overexpression also confers increased water stress resistance. What isapparent is that plant cytochrome P450s have diverse functions inregulating the biochemical activities in plant cells and are known inthe art.

The opium poppy P. somniferum is the plant from which opium isextracted. The opium poppy is the only commercially exploited poppy ofthe family Papaveraceae and is the principal source of natural opiates.The opium is extracted from latex harvested from the green seed pods. Afurther source of opiate alkaloids is the poppy straw which is the driedmature plant. P. somniferum is a source of clinically useful opiatealkaloids such as morphine, codeine, thebaine, noscapine [also known asnarcotine] and papaverine. The clinical application of these opiatealkaloids and their derivates is broad having use as analgesics, coughsuppressants and anti-spasmodics. Although not used as a pharmacologicalagent in its own right, thebaine is a particularly useful opiate whichcan be converted into a range of compounds such as hydrocodone,oxycodone, oxymorphone, nalbuphine naltrexone, buprenorphine andetorphine. These intermediates also have broad pharmaceuticalapplications. For example, oxycodone, oxymorphone and etorphine arewidely used as an analgesic for moderate to severe pain and are oftencombined with other analgesics such as ibuprofen. Buprenorphine is usedin the treatment of heroin addiction and chronic pain. Naltrexone isused in the treatment of alcohol and opiate addiction.

This disclosure relates to the identification and characterization ofcytochrome P450s isolated from a Papaver somniferum cultivar we callPSCYP1, PSCYP2 and PSCYP3. The predicted protein encoded by PSCYP1exhibits highest sequence identity to a cytochrome P450 from Coptisjaponica (GenBank accession no. BAF98472.1, 46% identity). The closesthomologue with an assignment to a cytochrome P450 subfamily is CYP82C4from Arabidopsis lyrata (NCBI reference seq no. XP_(—)002869304.1, 44%identity). The Arabidopsis thaliana CYP82C4 protein has been shown toadd a hydroxyl group to the 5 position of 8-methoxypsoralen, afurocoumarin, creating 5-hydroxy-8-methoxypsoralen (Kruse et al. (2008)Chemistry & Biology 15: 149-156). The closest homologues of thepredicted protein encoded by PSCYP2 are annotated as stylopine synthasesfrom Argemone mexicana (Gen Bank accession no. ABR14721, 77% identity),Papaver somniferum (GenBank accession no ADB89214, 76% identity) andEschscholzia californica (GenBank accession no. BAD98250, 72% identity).They belong to the CYP719A subfamily of cytochrome P450s which have onlybeen found in isoquinoline alkaloid-producing plant species where theycatalyse the formation of methylenedioxy-bridges (Ikezawa et al. (2009)Plant Cell Rep. 28:123-133). The closest homologue of the predictedprotein encoded by PSCYP3 is annotated as protopine 6-hydroxylase fromEschscholzia californica (GenBank accession no. BAK20464, 44% identity).The closest homologue with an assignment to a cytochrome P450 subfamilyis CYP82C4 from Arabidopsis lyrata mentioned above (42% identity).Surprisingly PSCYP1, PSCYP2 and PSCYP3 are unique to Papaver somniferumcultivars that produce noscapine. Those cultivars that do not producenoscapine do not include this gene.

STATEMENTS OF INVENTION

According to an aspect of the invention there is provided an isolatednucleic acid molecule that encodes a cytochrome P450 polypeptide whereinsaid nucleic acid molecule comprises or consists of a nucleotidesequence selected from the group consisting of:

-   -   i) a nucleotide sequence as represented by the sequence in FIG.        1 a, 1 b, 1 c, 1 d, 3 a, 3 b or 3 c;    -   ii) a nucleotide sequence wherein said sequence is degenerate as        a result of the genetic code to the nucleotide sequence defined        in (i);    -   iii) a nucleic acid molecule the complementary strand of which        hybridizes under stringent hybridization conditions to the        sequence in FIG. 1 a, 1 b, 1 c, 1 d, 3 a, 3 b or 3 c wherein        said nucleic acid molecule encodes a cytochrome P450        polypeptide;    -   iv) a nucleotide sequence that encodes a polypeptide comprising        an amino acid sequence as represented in FIG. 4 a, 4 b, 4 c or 4        d;    -   v) a nucleotide sequence that encodes a polypeptide comprising        an amino acid sequence wherein said amino acid sequence is        modified by addition deletion or substitution of at least one        amino acid residue as represented in iv) above and which has        retained or enhanced cytochrome P450 activity.

Hybridization of a nucleic acid molecule occurs when two complementarynucleic acid molecules undergo an amount of hydrogen bonding to eachother. The stringency of hybridization can vary according to theenvironmental conditions surrounding the nucleic acids, the nature ofthe hybridization method, and the composition and length of the nucleicacid molecules used. Calculations regarding hybridization conditionsrequired for attaining particular degrees of stringency are discussed inSambrook et al., Molecular Cloning: A Laboratory Manual (Cold SpringHarbor Laboratory Press, Cold Spring Harbor, N.Y., 2001); and Tijssen,Laboratory Techniques in Biochemistry and MolecularBiology—Hybridization with Nucleic Acid Probes Part I, Chapter 2(Elsevier, New York, 1993). The T_(m) is the temperature at which 50% ofa given strand of a nucleic acid molecule is hybridized to itscomplementary strand. The following is an exemplary set of hybridizationconditions and is not limiting:

Very High Stringency (Allows Sequences that Share at Least 90% Identityto Hybridize)

-   -   Hybridization: 5×SSC at 65° C. for 16 hours    -   Wash twice: 2×SSC at room temperature (RT) for 15 minutes each    -   Wash twice: 0.5×SSC at 65° C. for 20 minutes each        High Stringency (Allows Sequences that Share at Least 80%        Identity to Hybridize)    -   Hybridization: 5×-6×SSC at 65° C.-70° C. for 16-20 hours    -   Wash twice: 2×SSC at RT for 5-20 minutes each    -   Wash twice: 1×SSC at 55° C.-70° C. for 30 minutes each        Low Stringency (Allows Sequences that Share at Least 50%        Identity to Hybridize)    -   Hybridization: 6×SSC at RT to 55° C. for 16-20 hours    -   Wash at least twice: 2×-3×SSC at RT to 55° C. for 20-30 minutes        each.

In a preferred embodiment of the invention said nucleic acid moleculecomprises or consists of a nucleotide sequence as represented in FIG. 1a, 1 b, 1 c or 1 d.

According to a further aspect of the invention there is provided anisolated polypeptide selected from the group consisting of:

-   -   i) a polypeptide comprising or consisting of an amino acid        sequence as represented in FIG. 4 a, 4 b, 4 c or 4 d; or    -   ii) a modified polypeptide comprising or consisting of a        modified amino acid sequence wherein said polypeptide is        modified by addition deletion or substitution of at least one        amino acid residue of the sequence presented in FIG. 4 a, 4 b, 4        c or 4 d and which has retained or enhanced cytochrome P450        activity.

A modified polypeptide as herein disclosed may differ in amino acidsequence by one or more substitutions, additions, deletions, truncationsthat may be present in any combination. Among preferred variants arethose that vary from a reference polypeptide by conservative amino acidsubstitutions. Such substitutions are those that substitute a givenamino acid by another amino acid of like characteristics. The followingnon-limiting list of amino acids are considered conservativereplacements (similar): a) alanine, serine, and threonine; b) glutamicacid and aspartic acid; c) asparagine and glutamine d) arginine andlysine; e) isoleucine, leucine, methionine and valine and f)phenylalanine, tyrosine and tryptophan. Most highly preferred arevariants that retain or enhance the same biological function andactivity as the reference polypeptide from which it varies.

In one embodiment, the variant polypeptides have at least 43%, 45%, or47% identity, more preferably at least 50% identity, still morepreferably at least 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95% identity, andat least 99% identity with the full length amino acid sequenceillustrated herein.

According to a further aspect of the invention there is provided avector comprising a nucleic acid molecule encoding a cytochrome P450polypeptide according to the invention wherein said nucleic acidmolecule is operably linked to a nucleic acid molecule comprising apromoter sequence.

In a preferred embodiment of the invention said nucleic acid sequencecomprising a promoter confers constitutive expression on said cytochromeP450 polypeptide.

In an alternative preferred embodiment of the invention said nucleicacid molecule comprising a promoter confers regulated expression on saidcytochrome P450 polypeptide.

In a preferred embodiment of the invention said regulated expression istissue or developmentally regulated expression.

In a further alternative embodiment of the invention said regulatedexpression is inducible expression.

In an alternative embodiment of the invention a vector including anucleic acid molecule according to the invention need not include apromoter or other regulatory sequence, particularly if the vector is tobe used to introduce the nucleic acid molecule into cells forrecombination into the gene.

Preferably the nucleic acid molecule in the vector is under the controlof, and operably linked to, an appropriate promoter or other regulatoryelements for transcription in a host cell such as a microbial, (e.g.bacterial, yeast), or plant cell. The vector may be a bi-functionalexpression vector which functions in multiple hosts. In the case ofcytochrome P450 genomic DNA this may contain its own promoter or otherregulatory elements and in the case of cDNA this may be under thecontrol of an appropriate promoter or other regulatory elements forexpression in the host cell.

By “promoter” is meant a nucleotide sequence upstream from thetranscriptional initiation site and which contains all the regulatoryregions required for transcription. Suitable promoters includeconstitutive, tissue-specific, inducible, developmental or otherpromoters for expression in plant cells comprised in plants depending ondesign. Such promoters include viral, fungal, bacterial, animal andplant-derived promoters capable of functioning in plant cells.

Constitutive promoters include, for example CaMV 35S promoter (Odell etal. (1985) Nature 313, 9810-812); rice actin (McElroy et al. (1990)Plant Cell 2: 163-171); ubiquitin (Christian et al. (1989) Plant Mol.Biol. 18: (675-689); pEMU (Last et al. (1991) Theor Appl. Genet. 81:581-588); MAS (Velten et al. (1984) EMBO J. 3. 2723-2730); ALS promoter(U.S. application Ser. No. 08/409,297), and the like. Other constitutivepromoters include those in U.S. Pat. Nos. 5,608,149; 5,608,144;5,604,121; 5,569,597; 5,466,785; 5,399,680, 5,268,463; and 5,608,142,each of which is incorporated by reference.

Chemical-regulated promoters can be used to modulate the expression of agene in a plant through the application of an exogenous chemicalregulator. Depending upon the objective, the promoter may be achemical-inducible promoter, where application of the chemical inducedgene expression, or a chemical-repressible promoter, where applicationof the chemical represses gene expression. Chemical-inducible promotersare known in the art and include, but are not limited to, the maizeIn2-2 promoter, which is activated by benzenesulfonamide herbicidesafeners, the maize GST promoter, which is activated by hydrophobicelectrophilic compounds that are used as pre-emergent herbicides, andthe tobacco PR-1a promoter, which is activated by salicylic acid. Otherchemical-regulated promoters of interest include steroid-responsivepromoters (see, for example, the glucocorticoid-inducible promoter inSchena et al. (1991) Proc. Natl. Acad. Sci. USA 88: 10421-10425 andMcNellis et al. (1998) Plant J. 14(2): 247-257) andtetracycline-inducible and tetracycline-repressible promoters (see, forexample, Gatz et al. (1991) Mol. Gen. Genet. 227: 229-237, and U.S. Pat.Nos. 5,814,618 and 5,789,156, herein incorporated by reference.

Where enhanced expression in particular tissues is desired,tissue-specific promoters can be utilised. Tissue-specific promotersinclude those described by Yamamoto et al. (1997) Plant J. 12(2):255-265; Kawamata et al. (1997) Plant Cell Physiol. 38(7): 792-803;Hansen et al. (1997) Mol. Gen. Genet. 254(3): 337-343; Russell et al.(1997) Transgenic Res. 6(2): 157-168; Rinehart et al. (1996) PlantPhysiol. 112(3): 1331-1341; Van Camp et al. (1996) Plant Physiol.112(2): 525-535; Canevascni et al. (1996) Plant Physiol. 112(2):513-524; Yamamoto et al. (1994) Plant Cell Physiol. 35(5): 773-778; Lam(1994) Results Probl. Cell Differ. 20: 181-196; Orozco et al. (1993)Plant Mol. Biol. 23(6): 1129-1138; Mutsuoka et al. (1993) Proc. Natl.Acad. Sci. USA 90 (20): 9586-9590; and Guevara-Garcia et al (1993) PlantJ. 4(3): 495-50.

“Operably linked” means joined as part of the same nucleic acidmolecule, suitably positioned and oriented for transcription to beinitiated from the promoter. DNA operably linked to a promoter is “undertranscriptional initiation regulation” of the promoter. In a preferredaspect, the promoter is a tissue specific promoter, an induciblepromoter or a developmentally regulated promoter.

Particular of interest in the present context are nucleic acidconstructs which operate as plant vectors. Specific procedures andvectors previously used with wide success in plants are described byGuerineau and Mullineaux (1993) (Plant transformation and expressionvectors. In: Plant Molecular Biology Labfax (Croy RRD ed) Oxford, BIOSScientific Publishers, pp 121-148. Suitable vectors may include plantviral-derived vectors (see e.g. EP194809).

If desired, selectable genetic markers may be included in the construct,such as those that confer selectable phenotypes such as resistance toherbicides (e.g. kanamycin, hygromycin, phosphinotricin, chlorsulfuron,methotrexate, gentamycin, spectinomycin, imidazolinones and glyphosate).

According to a further aspect of the invention there is provided atransgenic cell transformed or transfected with a nucleic acid moleculeor vector according to the invention.

In a preferred embodiment of the invention said cell is a plant cell.

In a preferred embodiment of the invention said plant cell is from thefamily Papa veraceae.

In a preferred embodiment of the invention said plant cell is a Papaversomniferum cell.

According to a further aspect of the invention there is provided a plantcomprising a plant cell according to the invention.

In a preferred embodiment of the invention said plant is from the familyPapaveraceae; preferably Papaver somniferum.

In an alternative preferred embodiment of the invention said cell is amicrobial cell; preferably a bacterial or fungal cell [e.g. yeast,Saccharomyces cerevisiae].

In a preferred embodiment of the invention said cell is adapted suchthat the nucleic acid molecule encoding the cytochrome P450 isover-expressed when compared to a non-transgenic cell of the samespecies.

According to a further aspect of the invention there is provided anucleic acid molecule comprising a transcription cassette wherein saidcassette includes a nucleotide sequence designed with reference to FIG.1 a, 1 b, 1 c or 1 d and is adapted for expression by provision of atleast one promoter operably linked to said nucleotide sequence such thatboth sense and antisense molecules are transcribed from said cassette.

In a preferred embodiment of the invention said cassette is adapted suchthat both sense and antisense ribonucleic acid molecules are transcribedfrom said cassette wherein said sense and antisense nucleic acidmolecules are adapted to anneal over at least part or all of theirlength to form a small interfering RNA [siRNA] or short hairpin RNA[shRNA].

In a preferred embodiment of the invention said cassette is providedwith at least two promoters adapted to transcribe both sense andantisense strands of said ribonucleic acid molecule.

In an alternative preferred embodiment of the invention said cassettecomprises a nucleic acid molecule wherein said molecule comprises afirst part linked to a second part wherein said first and second partsare complementary over at least part of their sequence and furtherwherein transcription of said nucleic acid molecule produces anribonucleic acid molecule which forms a double stranded region bycomplementary base pairing of said first and second parts therebyforming an shRNA.

A technique to specifically ablate gene function is through theintroduction of double stranded RNA, also referred to as smallinhibitory/interfering RNA (siRNA) or short hairpin RNA [shRNA], into acell which results in the destruction of mRNA complementary to thesequence included in the siRNA/shRNA molecule. The siRNA moleculecomprises two complementary strands of RNA (a sense strand and anantisense strand) annealed to each other to form a double stranded RNAmolecule. The siRNA molecule is typically derived from exons of the genewhich is to be ablated. The mechanism of RNA interference is beingelucidated. Many organisms respond to the presence of double strandedRNA by activating a cascade that leads to the formation of siRNA. Thepresence of double stranded RNA activates a protein complex comprisingRNase III which processes the double stranded RNA into smaller fragments(siRNAs, approximately 21-29 nucleotides in length) which become part ofa ribonucleoprotein complex. The siRNA acts as a guide for the RNasecomplex to cleave mRNA complementary to the antisense strand of thesiRNA thereby resulting in destruction of the mRNA.

In a preferred embodiment of the invention said nucleic acid molecule ispart of a vector adapted for expression in a plant cell.

According to a further aspect of the invention there is provided a plantcell transfected with a nucleic acid molecule or vector according to theinvention wherein said cell has reduced expression of said cytochromeP450 polypeptide.

According to an aspect of the invention there is provided a process forthe modification of an opiate alkaloid comprising:

-   -   i) providing a transgenic plant cell according to the invention;    -   ii) cultivating said plant cell to produce a transgenic plant;        and optionally    -   i) harvesting said transgenic plant, or part thereof.

In a preferred method of the invention said harvested plant material isdried straw and said opiate alkaloid is extracted.

According to an alternative aspect of the invention there is provided aprocess for the modification of an opiate alkaloid comprising:

-   -   i) providing a transgenic microbial cell according to the        invention that expresses a cytochrome P450 according to the        invention in culture with at least one opiate alkaloid;    -   ii) cultivating the microbial cell under conditions that modify        one or more opiate alkaloids; and optionally    -   iii) isolating said modified alkaloid from the microbial cell or        cell culture.

In a preferred method of the invention said microbial cell is abacterial cell or fungal/yeast cell.

If microbial cells are used as organisms in the process according to theinvention they are grown or cultured in the manner with which theskilled worker is familiar, depending on the host organism. As a rule,microorganisms are grown in a liquid medium comprising a carbon source,usually in the form of sugars, a nitrogen source, usually in the form oforganic nitrogen sources such as yeast extract or salts such as ammoniumsulfate, trace elements such as salts of iron, manganese and magnesiumand, if appropriate, vitamins, at temperatures of between 0° C. and 100°C., preferably between 10° C. and 60° C., while gassing in oxygen.

The pH of the liquid medium can either be kept constant, that is to sayregulated during the culturing period, or not. The cultures can be grownbatchwise, semi-batchwise or continuously. Nutrients can be provided atthe beginning of the fermentation or fed in semi-continuously orcontinuously. The methylated opiate alkaloids produced can be isolatedfrom the organisms as described above by processes known to the skilledworker, for example by extraction, distillation, crystallization, ifappropriate precipitation with salt, and/or chromatography. To this end,the organisms can advantageously be disrupted beforehand. In thisprocess, the pH value is advantageously kept between pH 4 and 12,preferably between pH 6 and 9, especially preferably between pH 7 and 8.

The culture medium to be used must suitably meet the requirements of thestrains in question. Descriptions of culture media for variousmicroorganisms can be found in the textbook “Manual of Methods forGeneral Bacteriology” of the American Society for Bacteriology(Washington D.C., USA, 1981).

As described above, these media which can be employed in accordance withthe invention usually comprise one or more carbon sources, nitrogensources, inorganic salts, vitamins and/or trace elements.

Preferred carbon sources are sugars, such as mono-, di- orpolysaccharides. Examples of carbon sources are glucose, fructose,mannose, galactose, ribose, sorbose, ribulose, lactose, maltose,sucrose, raffinose, starch or cellulose. Sugars can also be added to themedia via complex compounds such as molasses or other by-products fromsugar refining. The addition of mixtures of a variety of carbon sourcesmay also be advantageous. Other possible carbon sources are oils andfats such as, for example, soya oil, sunflower oil, peanut oil and/orcoconut fat, fatty acids such as, for example, palmitic acid, stearicacid and/or linoleic acid, alcohols and/or polyalcohols such as, forexample, glycerol, methanol and/or ethanol, and/or organic acids suchas, for example, acetic acid and/or lactic acid.

Nitrogen sources are usually organic or inorganic nitrogen compounds ormaterials comprising these compounds. Examples of nitrogen sourcescomprise ammonia in liquid or gaseous form or ammonium salts such asammonium sulfate, ammonium chloride, ammonium phosphate, ammoniumcarbonate or ammonium nitrate, nitrates, urea, amino acids or complexnitrogen sources such as cornsteep liquor, soya meal, soya protein,yeast extract, meat extract and others. The nitrogen sources can be usedindividually or as a mixture.

Inorganic salt compounds which may be present in the media comprise thechloride, phosphorus and sulfate salts of calcium, magnesium, sodium,cobalt, molybdenum, potassium, manganese, zinc, copper and iron.

Inorganic sulfur-containing compounds such as, for example, sulfates,sulfites, dithionites, tetrathionates, thiosulfates, sulfides, or elseorganic sulfur compounds such as mercaptans and thiols may be used assources of sulfur for the production of sulfur-containing finechemicals, in particular of methionine.

Phosphoric acid, potassium dihydrogenphosphate or dipotassiumhydrogenphosphate or the corresponding sodium-containing salts may beused as sources of phosphorus.

Chelating agents may be added to the medium in order to keep the metalions in solution. Particularly suitable chelating agents comprisedihydroxyphenols such as catechol or protocatechuate and organic acidssuch as citric acid.

The fermentation media used according to the invention for culturingmicroorganisms usually also comprise other growth factors such asvitamins or growth promoters, which include, for example, biotin,riboflavin, thiamine, folic acid, nicotinic acid, panthothenate andpyridoxine. Growth factors and salts are frequently derived from complexmedia components such as yeast extract, molasses, cornsteep liquor andthe like. It is moreover possible to add suitable precursors to theculture medium. The exact composition of the media compounds heavilydepends on the particular experiment and is decided upon individuallyfor each specific case. Information on the optimization of media can befound in the textbook “Applied Microbiol. Physiology, A PracticalApproach” (Editors P. M. Rhodes, P. F. Stanbury, IRL Press (1997) pp.53-73, ISBN 0 19 963577 3). Growth media can also be obtained fromcommercial suppliers, for example Standard 1 (Merck) or BHI (brain heartinfusion, DIFCO) and the like.

All media components are sterilized, either by heat (20 min at 1.5 barand 121° C.) or by filter sterilization. The components may besterilized either together or, if required, separately. All mediacomponents may be present at the start of the cultivation or addedcontinuously or batchwise, as desired.

The culture temperature is normally between 15° C. and 45° C.,preferably at from 25° C. to 40° C., and may be kept constant or may bealtered during the experiment. The pH of the medium should be in therange from 5 to 8.5, preferably around 7.0. The pH for cultivation canbe controlled during cultivation by adding basic compounds such assodium hydroxide, potassium hydroxide, ammonia and aqueous ammonia oracidic compounds such as phosphoric acid or sulfuric acid. Foaming canbe controlled by employing antifoams such as, for example, fatty acidpolyglycol esters. To maintain the stability of plasmids it is possibleto add to the medium suitable substances having a selective effect, forexample antibiotics. Aerobic conditions are maintained by introducingoxygen or oxygen-containing gas mixtures such as, for example, ambientair into the culture. The temperature of the culture is normally 20° C.to 45° C. and preferably 25° C. to 40° C. The culture is continued untilformation of the desired product is at a maximum. This aim is normallyachieved within 10 to 160 hours.

The fermentation broth can then be processed further. The biomass may,according to requirement, be removed completely or partially from thefermentation broth by separation methods such as, for example,centrifugation, filtration, decanting or a combination of these methodsor be left completely in said broth. It is advantageous to process thebiomass after its separation.

However, the fermentation broth can also be thickened or concentratedwithout separating the cells, using known methods such as, for example,with the aid of a rotary evaporator, thin-film evaporator, falling-filmevaporator, by reverse osmosis or by nanofiltration. Finally, thisconcentrated fermentation broth can be processed to obtain the opiatealkaloids present therein.

According to a further aspect of the invention there is provided the useof a gene encoded by a nucleic acid molecule as represented by thenucleic acid sequence in FIG. 3 a, 3 b or 3 c, or a nucleic acidmolecule that hybridizes under stringent hybridization conditions to thenucleotide sequence in FIG. 3 a, 3 b or 3 c and encodes a polypeptidewith cytochrome P450 activity as a means to identify the presence orabsence of a gene that encodes said cytochrome P450 in a Papaveraceaeplant.

According to a further aspect of the invention there is provided amethod to determine the presence or absence of a gene according to theinvention in a Papaveraceae variety comprising:

-   -   i) obtaining a sample from a Papaveraceae plant;    -   ii) extracting genomic DNA from the plant; and    -   iii) analyzing the genomic DNA for the presence of a gene        comprising or consisting of a nucleotide sequence as represented        in FIG. 3 a, 3 b or 3 c.

Methods to analyze genomic DNA are well known in the art. For example,polymerase chain reaction methods using sequence specificoligonucleotide primers to amplify specific regions of the geneaccording to the invention. The extraction, isolation and restrictionanalysis using sequence specific restriction endonucleases followed byseparation and Southern blotting to analyze genomic structure have beenestablished for over thirty years. The analysis may be directed tointron or exon structure or upstream or downstream regions of the gene;e.g. promoter regions.

According to a further aspect of the invention there is provided the useof a gene encoded by a nucleic acid molecule as represented by thenucleic acid sequence in FIG. 3 a, 3 b or 3 c, or a nucleic acidmolecule that hybridizes under stringent hybridization conditions to thenucleotide sequence in FIG. 3 a, 3 b or 3 c and encodes a polypeptidewith cytochrome P450 activity as a means to identify a locus whereinsaid locus is associated with altered expression or activity of saidcytochrome P450.

Mutagenesis as a means to induce phenotypic changes in organisms is wellknown in the art and includes but is not limited to the use of mutagenicagents such as chemical mutagens [e.g. base analogues, deaminatingagents, DNA intercalating agents, alkylating agents, transposons,bromine, sodium azide] and physical mutagens [e.g. ionizing radiation,psoralen exposure combined with UV irradiation].

According to a further aspect of the invention there is provided amethod to produce a Papaveraceae plant variety that has alteredexpression of a cytochrome P450 polypeptide according to the inventioncomprising the steps of:

-   -   i) mutagenesis of wild-type seed from a plant that does express        said cytochrome P450 polypeptide;    -   ii) cultivation of the seed in i) to produce first and        subsequent generations of plants;    -   iii) obtaining seed from the first generation plant and        subsequent generations of plants;    -   iv) determining if the seed from said first and subsequent        generations of plants has altered nucleotide sequence and/or        altered expression of said cytochrome P450 polypeptide;    -   v) obtaining a sample and analysing the nucleic acid sequence of        a nucleic acid molecule selected from the group consisting of:        -   a) a nucleic acid molecule comprising a nucleotide sequence            as represented in FIG. 3 a, 3 b or 3 c;        -   b) a nucleic acid molecule that hybridises to the nucleic            acid molecule in a) under stringent hybridisation conditions            and that encodes a polypeptide with cytochrome P450            polypeptide activity; and optionally    -   vi) comparing the nucleotide sequence of the nucleic acid        molecule in said sample to a nucleotide sequence of a nucleic        acid molecule of the original wild-type plant.

In a preferred method of the invention said nucleic acid molecule isanalysed by a method comprising the steps of:

-   -   i) extracting nucleic acid from said mutated plants;    -   ii) amplification of a part of said nucleic acid molecule by a        polymerase chain reaction;    -   iii) forming a preparation comprising the amplified nucleic acid        and nucleic acid extracted from wild-type seed to form        heteroduplex nucleic acid;    -   iv) incubating said preparation with a single stranded nuclease        that cuts at a region of heteroduplex nucleic acid to identify        the mismatch in said heteroduplex; and    -   v) determining the site of the mismatch in said nucleic acid        heteroduplex.

In a preferred method of the invention said Papaveraceae plant varietyhas enhanced cytochrome P450 polypeptide expression and/or activity.

According to a further aspect of the invention there is provided a plantobtained by the method according to the invention.

According to an aspect of the invention there is provided a plantwherein said plant comprises a viral vector that includes all or part ofa gene comprising a nucleic acid molecule according to the invention.

In a preferred embodiment of the invention said gene is encoded by anucleic acid molecule comprising a nucleic acid sequence selected fromthe group consisting of:

-   -   i) a nucleic acid molecule comprising a nucleotide sequence as        represented in FIG. 1 a, 1 b, 1 c or 1 d;    -   ii) a nucleic acid molecule comprising a nucleotide sequence        that hybridises under stringent hybridisation conditions to a        nucleic acid molecule in (i) and which encodes a cytochrome p450        polypeptide;    -   iii) a nucleic acid molecule that encodes a variant polypeptide        that varies from a polypeptide comprising the amino acid        sequence as represented in FIG. 4 a, 4 b, 4 c, or 4 d.

In a preferred embodiment of the invention said nucleic acid moleculecomprises or consists of a nucleotide sequence as represented in FIG. 1a.

In a preferred embodiment of the invention said nucleic acid moleculecomprises or consists of a nucleotide sequence as represented in FIG. 1b.

In a preferred embodiment of the invention said nucleic acid moleculecomprises or consists of a nucleotide sequence as represented in FIG. 1c

In a preferred embodiment of the invention said nucleic acid moleculecomprises or consists of a nucleotide sequence as represented in FIG. 1d.

In a preferred embodiment of the invention said nucleic acid moleculeconsists of a nucleotide sequence as represented in FIG. 12.

In an alternative preferred embodiment of the invention said nucleicacid molecule consists of a nucleotide sequence as represented in FIG.13.

According to a further aspect of the invention there is provided a viralvector comprising all or part of a nucleic acid molecule according tothe invention.

According to an aspect of the invention there is provided the use of aviral vector according to the invention in viral induced gene silencingin a plant.

In a preferred embodiment of the invention said plant is from the familyPapaveraceae.

Virus induced gene silencing [VIGS] is known in the art and exploits aRNA mediated antiviral defense mechanism. Plants that are infected withan unmodified virus induce a mechanism that specifically targets theviral genome. However, viral vectors which are engineered to includenucleic acid molecules derived from host plant genes also inducespecific inhibition of viral vector expression and additionally targethost mRNA. This allows gene specific gene silencing without geneticmodification of the plant genome and is essentially a non-transgenicmodification.

Throughout the description and claims of this specification, the words“comprise” and “contain” and variations of the words, for example“comprising” and “comprises”, means “including but not limited to”, andis not intended to (and does not) exclude other moieties, additives,components, integers or steps.

Throughout the description and claims of this specification, thesingular encompasses the plural unless the context otherwise requires.In particular, where the indefinite article is used, the specificationis to be understood as contemplating plurality as well as singularity,unless the context requires otherwise.

Features, integers, characteristics, compounds, chemical moieties orgroups described in conjunction with a particular aspect, embodiment orexample of the invention are to be understood to be applicable to anyother aspect, embodiment or example described herein unless incompatibletherewith.

An embodiment of the invention will now be described by example only andwith reference to the following figures:

FIG. 1 a is nucleotide sequence of a cDNA that encodes PSCYP1, FIG. 1 bis nucleotide sequence of a cDNA that encodes PSCYP2, FIG. 1 c isnucleotide sequence of a cDNA that encodes PSCYP3; FIG. 1 d isnucleotide sequence of another embodiment of a cDNA that encodes PSCYP3;

FIG. 2 a illustrates the frequency of ESTs of the PSCYP1 gene in ESTlibraries derived from 454 sequencing of stem and capsule tissues fromcultivars GSK MORPHINE CVS1, GSK MORPHINE CVS2, GSK NOSCAPINE CVS1 andGSK THEBAINE CVS1. The 16 EST libraries were generated by pyrosequencingusing cDNA libraries prepared from stems (S) and capsules (C) at twodevelopmental stages ‘early harvest’ (EH, 1-3 days after petals hadfallen off) and ‘late-harvest’ (LH, 4-6 days after petals had fallenoff) from each of the four P. somniferum cultivars; FIG. 2 b illustratesthe frequency of ESTs of the PSCYP2 gene; FIG. 2 c illustrates thefrequency of ESTs of the PSCYP3 gene;

FIG. 3 a is the nucleotide sequence of the gene encoding PSCYP1; FIG. 3b is the nucleotide sequence of the gene encoding PSCYP2, FIG. 3 c isthe nucleotide sequence of the gene encoding PSCYP3;

FIG. 4 a is the deduced amino acid sequence of PSCYP1; FIG. 4 b is thededuced amino acid sequence of PSCYP2; FIG. 4 c is the deduced aminoacid sequence of PSCYP3; FIG. 4 d is the deduced amino acid sequence ofPSCYP3;

FIG. 5 illustrates that the PSCYP1 gene sequence is only present incultivar GSK NOSCAPINE CVS1 and is absent from cultivars GSK MORPHINECVS1, GSK MORPHINE CVS2 and GSK THEBAINE CVS1;

FIG. 6 illustrates that the PSCYP2 gene sequence is only present incultivar GSK NOSCAPINE CVS1 and is absent from cultivars GSK MORPHINECVS1, GSK MORPHINE CVS2 and GSK THEBAINE CVS1;

FIG. 7 illustrates that the PSCYP3 gene sequence is only present incultivar GSK NOSCAPINE CVS1 and is absent from cultivars GSK MORPHINECVS1, GSK MORPHINE CVS2 and GSK THEBAINE CVS1;

FIG. 8 a is a tabular representation of the segregation of the PSCYP1gene in an F2 mapping population derived from a parental cross ofcultivars GSK NOSCAPINE CVS1 and GSK THEBAINE CVS1 along with theco-segregation of PSCYP1 and noscapine accumulation in individual F2plants, FIG. 8 b is the equivalent representation of the segregation ofthe PSCYP2 gene, FIG. 8 c is the equivalent representation of thesegregation of the PSCYP3 gene, the PSCYP3 genotyping assay failed on 16samples (as indicated by the failure to amplify the internal positivecontrol), these samples were excluded from the PSCYP3 co-segregationanalysis;

FIG. 9 illustrates a typical UPLC chromatogram for standard solution;

FIG. 10 illustrates a typical UPLC chromatogram for a noscapinecontaining poppy variety;

FIG. 11 is the 622 bases long part of the phytoene desaturase genesequence amplified from cDNA of GSK NOSCAPINE CVS1. The sequence stretchof 129 bases used to silence the phytoene desaturase gene is underlined;

FIG. 12 is the part of the cDNA sequence used to silence PSCYP2; and

FIG. 13 is the part of the cDNA sequence used to silence PSCYP3;

FIG. 14 shows the normalised peak area of putative tetrahydrocolumbaminein the UPLC chromatograms obtained from latex and mature capsules ofplants that displayed the photo-bleaching phenotype after infection withthe silencing constructs pTRV2-PDS-PSCYP2, pTRV2-PDS-PSCYP3 orpTRV2-PDS, respectively. The putative tetrahydrocolumbamine peak areaobtained from uninfected plants is shown as well;

FIG. 15 shows the normalised peak area of a putative secoberbinealkaloid (in the UPLC chromatograms obtained from latex and maturecapsules of plants that displayed the photo-bleaching phenotype afterinfection with the silencing constructs pTRV2-PDS-PSCYP2,pTRV2-PDS-PSCYP3 or pTRV2-PDS, respectively. The putative secoberbinepeak area obtained from uninfected plants is shown as well. The mass,molecular formula and fragmentation pattern of the compound isconsistent with demethoxyhydroxymacrantaldehyde ordemethoxymacrantoridine; and

FIG. 16 shows the normalised peak area of another putative secoberbinealkaloid in the UPLC chromatograms obtained from latex and maturecapsules of plants that displayed the photo-bleaching phenotype afterinfection with the silencing constructs pTRV2-PDS-PSCYP2,pTRV2-PDS-PSCYP3 or pTRV2-PDS, respectively. The putative secoberbinepeak area obtained from uninfected plants is shown as well. The mass,molecular formula and fragmentation pattern of the compound isconsistent with either demethoxynarcotinediol or narctololinol.

Materials and Methods

Generation of EST librariesa) RNA Isolation and cDNA Synthesis

Material was harvested from stems and capsules at two developmentalstages from four poppy cultivars. RNA was prepared individually fromfive plants per cultivar, developmental stage and organ. The harvestedmaterial was ground in liquid nitrogen using a mortar and pestle. RNAwas isolated from the ground stem or capsule preparations using a CTAB(hexadecyltrimethylammonium bromide) based method as described in Changet al. (1993) Plant Molecular Rep. 11: 113-116 with slight modifications(three extractions with chloroform:isoamylalcohol, RNA precipitationwith Lithium chloride at −20° C. over night). RNA was quantifiedspectrophotometrically before pooling equal amounts of RNA from fiveplants per cultivar, stage and organ. The pooled samples underwent afinal purification step using an RNeasy Plus MicroKit (Qiagen, Crawley,UK) to remove any remaining genomic DNA from the preparations. RNA wastypically eluted in 30-100 μl water. cDNA was prepared using a SMARTcDNA Library Construction Kit (Clontech, Saint-Germainen-Laye, France)according to the manufacturer's instructions but using SuperScript IIReverse Transcriptase (Invitrogen, Paisley, UK) for first strandsynthesis. The CDSIII PCR primer was modified to: 5′ ATT CTA GAT CCR ACATGT TTT TTT TTT TTT TTT TTT TVN 3′ where R=A or G, V=A, C or G; N=A/T orC/G. cDNA was digested with Mmel (New England Biolabs Inc., Hitchin, UK)followed by a final purification using a QIAquick PCR Purification kit(Qiagen, Crawley, UK).

b) cDNA Pyrosequencing

The Roche 454 GS-FLX sequencing platform (Branford, Conn., USA) was usedto perform pyrosequencing on cDNA samples prepared from the followingmaterials for each of the four P. somniferum cultivars—GSK MORPHINECVS1, GSK MORPHINE CVS2, GSK NOSCAPINE CVS1 and GSK THEBAINE CVS1.

1. Stem, 1-3 days after petal fall (early harvest)2. Stem, 4-6 days after petal fall (late harvest)3. Capsule, 1-3 days after petal fall (early harvest)4. Capsule, 4-6 days after petal fall (late harvest)

c) Raw Sequence Analysis, Contiguous Sequence Assembly and Annotation

The raw sequence datasets were derived from parallel tagged sequencingon the 454 sequencing platform (Meyer et al. (2008) Nature Protocols 3:267-278). Primer and tag sequences were first removed from allindividual sequence reads. Contiguous sequence assembly was onlyperformed on sequences longer than 40 nucleotides and containing lessthan 3% unknown (N) residues. These high quality EST sequences wereassembled into unique contiguous sequences with the CAPS SequenceAssembly Program (Huang and Madan (1999) Genome Research 9: 868-877),and the resulting contigs were annotated locally using the BLAST2program (Altschul et al. (1997) Nucleic Acids Res. 25: 3389-3402)against the non-redundant peptide database downloaded from the NCBI.

d) Expression Profiling of the Cytochrome P450 Genes

The number of ESTs associated with the respective cytochrome P450 geneconsensus sequences were counted in each of the 16 EST libraries. Thevalues obtained were normalised on the basis of the total number of ESTsobtained per library.

Amplification and Sequencing of the Cytochrome P450 Genes from GSKNOSCAPINE CVS1 Genomic DNA.

a) Genomic DNA Preparation

DNA preparation: Leaf samples (30-50 mg) for DNA extraction wereharvested from plants of GSK MORPHINE CVS1, GSK MORPHINE CVS2 GSKNOSCAPINE CVS1, GSK THEBAINE CVS1 grown in the glasshouse. DNA wasextracted using Qiagen BioSprint 96. Extracted DNA was quantified usingHoescht 33258 and normalized to 10 ng/ul.

b) Amplification and sequencing of the cytochrome P450 genes from DNA ofGSK NOSCAPINE CVS1 Primers and primer combinations used foramplification of the respective cytochrome P450 genes from the extractedgenomic DNA are shown in Table 1. Primers were designed based on therespective cytochrome P450 contigs assembled from ESTs unique tocultivar GSK NOSCAPINE CVS1. The PSCYP1 and PSCYP2 contigs contained thecomplete open reading frame of as well as 5′ and 3′ untranslatedregions. PSCYP3 was represented by two contigs covering the 5′- and3′-ends of the open reading frame with 200 bases from the centre of theopen reading frame missing. This missing stretch of coding sequence wasamplified and confirmed by amplification and sequencing from cDNA(prepared as described above) in addition to genomic DNA to determinethe precise position and of intron 1 (FIG. 3 c). Amplification wereperformed on pools of DNA comprising the DNA of at least fourindividuals and the primer combinations shown in Table 2. The PCRconditions were as follows:

Reaction Mixture:

5 × HF buffer (Finnzymes) 5 μl dNTPs (20 mM each) 0.25 μl Fwd primer (10μM) 2.5 μl Rev primer (10 μM) 2.5 μl DNA (10 ng/μl) 5 μl Phusion HotStart (Finnzymes) 0.25 μl dH₂O 9.5 μl

Reaction volume: 25 μl

Phusion Hot Start from Finnzymes was purchased through New EnglandBiolabs, (Bishops Stortford, UK).

PCR Program:

initial denaturation 98° C. 1 min 30 cycles of: denaturation 98° C. 30sec annealing temperature Table 2&3 30 sec extension 72° C. 40 sec finalextension 72° C. 10 min incubation  4° C. storage

The 5′-end and part of the promoter region of PSCYP3 was amplified fromgenomic DNA via a long range PCR set up using primers PSCYP1_LA_R1 andPSCYP3_LA_R1:

Long Range PCR Reaction Mixture:

5 × LongAmp buffer (New England Biolabs) 10 μl dNTPs (10 mM each) 1.5 μlFwd primer (10 μM) 2 μl Rev primer (10 μM) 2 μl gDNA (100 ng/μl) 2 μlLongAmp Taq (New England Biolabs) 2 μl dH₂O 30.5 μl

Reaction volume: 50 μl

Lone Range PCR Program:

initial denaturation 94° C. 30 sec 30 cycles of: denaturation 94° C. 30sec annealing & extension 65° C. 13.5 min final extension 65° C. 10 minincubation  4° C. storage

The products resulting from the various PCRs were purified using theAgencourt AMPure purification kit (Beckman Coulter LTD, Bromley, UK).30-50 ng of the respective purified PCR products were subjected toSanger-sequencing using the primers shown in Table 2 as sequencingprimers. Since primer combination PSCYP1_F4/R7 resulted in amplificationof a smaller, unspecific product in addition to the expected amplicon(see also FIG. 4 d), the latter was excised and purified from the gelusing QIAEX II Gel Extraction Kit (Qiagen, Hilden, Germany) prior tosequencing.

The amino acid sequences of the respective cytochrome P450s, predictedfrom the Sanger-sequence confirmed open reading frame sequences, werecompared to protein sequences deposited in the non-redundant proteindatabase using the Standard Protein BLAST program (blastp).

c) Analysis of Genomic DNA from GSK MORPHINE CVS1, GSK MORPHINE CVS2,GSK NOSCAPINE CVS1 and GSK THEBAINE CVS1 for the Presence of CytochromeP450 Genes

To investigate if the cytochrome P450 genes were present in all fourcultivars, amplification from genomic DNA (pools of four individuals percultivar) of GSK MORPHINE CVS1, GSK MORPHINE CVS2, GSK NOSCAPINE CVS1and GSK THEBAINE CVS1 was performed in a series of overlapping fragmentsusing primer combinations shown in Table 3. Exactly the same PCRconditions as described above to obtain the full length genomicsequences from GSK NOSCAPINE CVS1 were used. =. 5 μl of each PCRreaction was resolved on 1% agarose alongside an appropriate sizestandards.

Generation of a Mapping Population, Extraction and Analysis of GenomicDNA from Leaf Material Plus Extraction and Analysis of Alkaloids fromPoppy Strawa) DNA Extraction from F2 Plants

40-50 mg of leaf tissue was harvested, in duplicate, from all poppyplants within the GSK NOSCAPINE CVS1 X GSK THEBAINE CVS1 F2 mappingpopulation and parental plants) at the ‘small rosette’ growth stage (˜10leaves present on each plant).

Leaf tissue (40-50 mg wet weight) was collected into 1.2 ml sample tubesin 8×12 format (Part Number 1760-00, Scientific Specialties Inc, 130Thurman St, Lodi, Calif. 95240 USA), closed with strip caps (Part Number1702-00, Scientific Specialties Inc) and shipped to the AGRF (AustralianGenome Research Facility) Adelaide on Techni-Ice dry Ice packs byovernight courier.

On receipt, strip caps were removed and a 3 mm tungsten carbide bead wasadded to each tube (Part Number 69997, Qiagen GmbH, Hilden, Germany).Samples were placed at −80° C. (Freezer model; Sanyo MDF-U73V) for aminimum of two hours prior to freeze-drying for 18 hr (Christ ModelAlpha 2-4 LSC).

Following freeze drying, tubes were sealed with fresh strip caps (asabove), and samples were powdered by bead-milling (Model “Tissue Lyser”,Part Number 85300; Qiagen) at 3,000 RPM for 2×60 sec cycles separated byplate inversion. DNA extraction was performed using the “NucleospinPlant II” system (Macherey-Nagel, GmbH & Co. KG Neumann-Neander-Straβe6-8, 52355 Düren, Germany).

Cell lysis was performed using the supplied Buffer Set PL2/3. Themanufacturer's protocol for centrifugal extraction was followed(Centrifuge model 4-K 15; Sigma Laborzentrifugen GmbH, 37520 Osterode amHarz, Germany).

The recovered DNA (12/96 samples, one sample per plate column) waschecked for quality and quantity by ultra violet spectroscopy (ModelNanodrop-8000; NanoDrop products, 3411 Silverside Rd, Bancroft Building;Wilmington, Del. 19810, USA) at 230, 260 and 280 nM.

b) Genotyping of F2 DNA Samples for the Presence of Absence of theCytochrome P450 Genes

DNA samples from a total of 275 F2 plants were genotyped for thepresence or absence of PSCYP1, PSCYP2 and PSCYP3, respectively, byamplifying a short fragment of each of the genes. In order tofluorescently label the resulting PCR fragments, the forward primerscarried a VIC-label (Applied Biosystems, UK) at their 5′-prime ends.Fragment analyses were carried out on the 96-capillary electrophoresis3730xl DNA Analyzer (Applied Biosystems, UK) according to themanufacturer's instructions. In addition to the respective cytochromeP450 fragments, an internal positive control was amplified in each PCRassay in order to distinguish lack of amplification due to absence ofthe cytochrome P450 genes in the DNA samples from lack of amplificationcaused by PCR assay failures. Samples were the PCR assay had failed wereexcluded from the co-segregation analyses of the genes with thenoscapine trait.

The following primers were used (primer sequences are shown in Table 1;forward primers were 5′-end-labeled with VIC):

PSCYP1: VIC-PSCYP1_F3/PSCYP1_R2; amplified fragment size: 166 bpPSCYP2: VIC-PSCYP2_F2/PSCYP2_R1; amplified fragment size: 226 bpPSCYP3: VIC-PSCYP3_F3/PSCYP3_R1; amplified fragment size: 638 bp

The PSCYP1-fragment was amplified with the following PCR conditions:

Reaction Mixture:

5 × GoTaq Buffer (Promega) 2 μl dNTPs (2.5 mM mix) 0.5 μl MgCl₂ (25 mM)0.6 μl Forward primer (10 μM) 0.5 μl Reverse primer (10 μM) 0.5 μl gDNA(5 ng/μl) 2 μl GoTaq (Promega) 0.2 μl dH₂O 3.7 μl

Reaction volume: 10 μl

PCR Program:

initial denaturation 94° C. 1 min 30 cycles of: denaturation 94° C. 30sec annealing temperature 62° C. 30 sec extension 72° C. 20-30 sec finalextension 72° C. 5 min incubation  4° C. storage

The PSCYP2- and PSCYP3-fragments were amplified with the following PCRconditions:

Reaction Mixture:

5 × Type-it multiplex PCR mix (Qiagen) 5 μl Forward primer (10 μM) 0.5μl Reverse primer (10 μM) 0.5 μl gDNA (5 ng/μl) 2 μl dH₂O 2 μl

Reaction volume: 10 μl

PCR Program:

initial denaturation 95° C. 15 min 30 cycles of: denaturation 95° C. 15sec annealing temperature 60° C. 30 sec extension 72° C. 30 sec finalextension 72° C. 5 min incubation  4° C. storage

c) Poppy Straw Analysis

Poppy capsules were harvested by hand from the mapping population oncecapsules had dried to approximately 10% moisture on the plant. The seedwas manually separated from the capsule, and capsule straw material(Poppy Straw) was then shipped to the GSK extraction facility in PortFairy, Australia.

The poppy straw samples were then ground in a Retsch Model MM04 ballmill into a fine powder. Two gram samples of ground poppy straw werethen weighed accurately (2±0.003 g) and extracted in 50 mL of a 10%acetic acid solution. The extraction suspension was shaken on an orbitalshaker at 200 rpm for a minimum of 10 minutes then filtered to provide aclear filtrate. The final filtrate was passed through a 0.22 μm filterprior to analysis.

The solutions were analysed using a Waters Acquity UPLC system fittedwith a Waters Acquity BEH C18 column, 2.1 mm×100 mm with 1.7 micronpacking. The mobile phase used a gradient profile with eluent Aconsisting of 0.1% Trifluoroacetic acid in deionised water and eluent Bconsisting of 100% Acetonitrile. The mobile phase gradient conditionsused are as listed in Table 2, the gradient curve number as determinedusing a Waters Empower chromatography software package. The flow ratewas 0.6 mL per minute and the column maintained at 45 C. The injectionvolume was 1 μL injection volume and the alkaloids were detected using aUV detector at 285 nm.

The loss on drying (LOD) of the straw was determined by drying in anoven at 105 degrees centrigrade for 3 hours.

Gradient Flow Program

Flow TIME (minutes) % Eluent A % Eluent B (mL/min) Curve No 0.00 95.05.0 0.60 INITIAL 0.80 90.0 10.0 0.60 6 3.40 75.0 25.0 0.60 3 3.60 95.05.0 0.60 6 4.00 95.0 5.0 0.60 11

Alkaloid concentrations for morphine, codeine, thebaine, oripavine andnoscapine were determined by comparison with standard solutions and theresults calculated on a dry weight basis.

Typical retention times are as follows:

Compound Retention Time (minutes) Morphine 1.14 Pseudo morphine 1.26Codeine 1.69 Oripavine 1.80 10-Hydroxythebaine 2.32 Thebaine 2.53Noscapine 3.16

Virus Induced Gene Silencing (VIGS) of PSCYP3 and PSCYP3 a) Generationof Silencing Constructs

A tobacco rattle virus (TRV) based virus induced gene silencing systemdeveloped and described by Liu et al. (2002) Plant J. 30(4): 415-429 wasused to investigate the gene function of PSCYP2 and PSCYP3. DNAfragments selected for silencing of PSCYP2 and PSCYP3, respectively,were amplified by PCR and cloned into the silencing vector pTRV2(GenBank accession no. AF406991; Liu et al. (2002) Plant J. 30(4):415-429). They were linked to a 129 bp-long fragment of the P.somniferum phytoene desaturase gene (PsPDS) in order to silence therespective cytochrome P450 genes and PsPDS simultaneously. Plantsdisplaying the photo-bleaching phenotype that resulted from silencing ofPsPDS (Hileman et al. (2005) Plant J. 44(2): 334-341) were identified asplants successfully infected with the respective silencing constructsand selected for analysis.

Generation of the pTRV2-PDS construct: A 622 bp fragment (FIG. 11) ofPsPDS was amplified from cDNA prepared from GSK NOSCAPINE CVS1 asdescribed above using primers ps_pds_F and ps_pds_R4 (Table 4). Thesequence of the forward primer was based on a 412 bp long contig derivedfrom the EST-libraries which shared 99% identity at its 3′ end with thepartial coding sequence of the P. somniferum phytoene desaturase(GenBank accession no. DQ116056). The sequence of the reverse primer wasdesigned based on the DQ116056 sequence. The PCR conditions wereidentical to those described above for the amplification of thecytochrome P450 genes from genomic sequence except that the annealingstep was carried out at 70° C. and the extension time was increased to60 seconds.

Sau3Al digestion of the PCR-fragment yielded among others two fragments(280 bp and 129 bp in length) that carried BamHI-compatible sticky endsat both, their 5′ and 3′ ends. The 129 bp long fragment (underlinedstretch in FIG. 11) was cloned into the BamHI site of the pTRV2 vector.Because Sau3Al was used to produce BamHI-compatible sticky ends, theBamHI site at the 5-end of the PDS-insert was abolished in thepYL156-PDS construct. However, the BamHI recognition site at its 3′-endwas kept intact due to the nature of the PDS-insert sequence.

A sequence-confirmed pTRV2-PDS construct, with the 129 bp fragment insense orientation, was subsequently used as a vector for generating thePSCYP2 and PSCYP3 silencing constructs, and served as a control in theVIGS experiments.

Generation of silencing constructs for PSCYP2 and PSCYP3(pTRV2-PDS-PSCYP2 and pTRV2-PDS-PSCYP3): The DNA fragments selected forsilencing PSCYP2 and PSCYP3 were amplified from cDNA of GSK NOSCAPINECVS1 prepared as described above with the use of the primer sequencesshown in Table 4. Additional restriction sites (forward primers: XhoIand HindIII for forward primers; KpnI site for reverse primers) wereadded to the gene-specific primers in order to facilitate cloning. Theamplification conditions were as described above for amplifying thePDS-fragment except that the annealing temperatures were 60.9° C. forPSCYP2 and 66° C. for PSCYP3 and the extension time was 30 seconds.

The sequence selected to silence PSCYP2 (FIG. 12) and PSCYP3 (FIG. 12),respectively, were cloned into pTV00 (Ratcliff et al. (2001) Plant J.25(2): 237-245) using HindIII and KpnI and subcloned into pTRV2-PDSusing BamHI and KpnI. Sequence-confirmed pTRV2-PDS-PSCYP2 andpTRV2-PDS-PSCYP3 constructs were used in the VIGS experiments.

b) Transformation of Constructs into Agrobacterium tumefaciens

The propagation of the silencing constructs was carried out with the E.coli strain DH5α and, subsequently, the respective silencing constructs,as well as pTRV1 (Gen Bank accession no. AF406990; Liu et al. (2002)Plant J. 30(4): 415-429) were independently transformed intoelectrocompetent Agrobacterium tumefaciens (strain GV3101).

c) Infiltration of Plants

Overnight liquid cultures of A. tumefaciens containing each silencingconstruct were used to inoculate Luria-Bertani (LB) medium containing 10mM MES, 20 μM acetosyringone and 50 μg/ml kanamycin. Cultures weremaintained at 28° C. for 24 hours, harvested by centrifugation at 3000 gfor 20 min, and resuspended in infiltration solution (10 mM MES, 200 μMacetosyringone, 10 mM MgCl2) to an OD600 of 2.5. A. tumefaciensharbouring the respective constructs (pTRV2-PDS-PSCYP2, pTRV2-PDS-PSCYP3or, as a control, pTRV2-PDS) were each mixed 1:1 (v/v) with A.tumefaciens containing pTRV1, and incubated for two hours at 22° C.prior to infiltration. Two weeks old seedlings of GSK NOSCAPINE CVS1grown under standard greenhouse conditions (22° C., 16 h photoperiod),with emerging first leaves, were infiltrated as described by Hagel andFacchini (2010) Nat. Chem. Biol. 6: 273-275.

d) Latex and Capsule Analysis of Silenced Plants

Leaf latex of infiltrated opium poppy plants displaying photo-bleachingas a visual marker for successful infection and silencing was analysedwhen the first flower buds emerged (˜7 week old plants). Plants showinga similar degree of photo-bleaching of leaves were selected foranalysis.

Latex was collected from cut petioles, with a single drop dispersed into500 μL 10% acetic acid. This was diluted 10× in 1% acetic acid to givean alkaloid solution in 2% acetic acid for further analysis. Capsuleswere harvested by hand from glasshouse-grown from the same plants usedfor latex analysis and single capsules were ground in a Retsch ModelMM04 ball mill into a fine powder. Ten mg samples of ground poppy strawwere then weighed accurately (10±0.1 mg) and extracted in 0.5 mL of a10% acetic acid solution with gentle shaking for 1 h at roomtemperature. Samples were then clarified by centrifugation and a 50 μLsubsample diluted 10× in 1% acetic acid to give an alkaloid solution in2% acetic acid for further analysis.

All solutions were analysed using a Waters Acquity UPLC system fittedwith a Waters Acquity BEH C18 column, 2.1 mm×100 mm with 1.7 micronpacking. The mobile phase used a gradient profile with eluent Aconsisting of 10 mM ammonium bicarbonate pH 10.2 and eluent B methanol.The mobile phase gradient conditions used are as listed in Table 1, witha linear gradient. The flow rate was 0.5 mL per minute and the columnmaintained at 60° C. The injection volume was 2 μL and eluted peaks wereionised in positive APCI mode and detected within ˜3 ppm mass accuracyusing a Thermo LTQ-Orbitrap. The runs were controlled by Thermo Xcalibursoftware.

Gradient Flow Program:

Flow TIME (minutes) % Eluent A % Eluent B (mL/min) 0.0 98.0 2.0 0.50 0.298.0 2.0 0.50 0.5 60.0 40 0.50 4.0 20.0 80.0 0.50 4.5 20.0 0.0 0.50

All data analysis was carried out in R. Putative alkaloid peaks werequantified by their pseudomolecular ion areas using custom scripts. Peaklists were compiled and any peak-wise significant differences betweensamples were identified using 1-way ANOVA with p-values adjusted usingthe Bonferroni correction for the number of unique peaks in the dataset. For any peak-wise comparisons with adjusted p-values <0.05, Tukey'sHSD test was used to identify peaks that were significantly differentbetween any given sample and the control. Alkaloids were identified bycomparing exact mass and retention time values to those of standards.Where standards were not available, neutral exact masses were used togenerate molecular formulae hits within elemental constraints ofC=1:100, H=1:200, O=0:200, N=0:3 and mass accuracy <20 ppm. The hit withthe lowest ppm error within these constraints was used to assign aputative formula.

EXAMPLE 1 Assembly of Full Length PSCYP1 cDNA Sequence from ESTs andConfirmation by Sequencing from Genomic DNA

The full length open reading frame of PSCYP1 (FIG. 1 a) was assembledfrom ESTs derived from the 454 sequencing platform using the CAP3sequence assembly programme. The full length cDNA sequence was confirmedby direct amplification of the full length cDNA from GSK NOSCAPINE CVS1genomic DNA.

EXAMPLE 2 PSCYP1 is Exclusively Expressed in the Noscapine ProducingPapaver somniferum Cultivar GSK NOSCAPINE CVS1

FIG. 2 a shows the normalized distribution of ESTs associated with thePSCYP1 consensus sequence across each of the 16 EST libraries preparedfrom two organs (capsules and stems) at two developmental stages (earlyand late harvest) from each of the four poppy cultivars, GSK MORPHINECVS1, GSK MORPHINE CVS2, GSK NOSCAPINE CVS1 and GSK THEBAINE CVS1. ESTscorresponding to PSCYP1 were exclusively found in libraries derived fromthe noscapine producing cultivar GSK NOSCAPINE CVS1 (FIG. 2 a). PSCYP1expression was strongest in stem tissue shortly after flowering.

EXAMPLE 3 PCR-Amplification of PSCYP1 from Genomic DNA of the FourPapaver somniferum Cultivars GSK MORPHINE CVS1, GSK MORPHINE CVS2, GSKNOSCAPINE CVS1 and GSK THEBAINE CVS1

PCR-amplifications of PSCYP1 fragments were performed on genomic DNAfrom the four poppy cultivars GSK MORPHINE CVS1, GSK MORPHINE CVS2, GSKNOSCAPINE CVS1 and GSK THEBAINE CVS1 using the primer combinations shownin Table 2 and 3.

FIG. 5 shows the PCR-amplification of PSCYP1 from genomic DNA of thefour Papaver somniferum cultivars GSK MORPHINE CVS1, GSK MORPHINE CVS2,GSK NOSCAPINE CVS1 and GSK THEBAINE CVS1;

The amplification from genomic DNA yielded the gene sequence shown inFIG. 3 a.

EXAMPLE 4 The Putative Protein Encoded by PSCYP1 Shows Highest SequenceSimilarity to a Cytochrome P450 from Coptis japonica and Thalictrumflavum

The closest homologues to the putative protein encoded by the PSCYP1open reading frame (FIG. 4 a) are a cytochrome P450 from Coptis japonica(Gen Bank accession no. BAF98472.1, 46% identical at amino acid level).The closest homologue with an assignment to a cytochrome P450 subfamilyis CYP82C4 from Arabidopsis lyrata (GenBank accession no.XP_(—)002869304.1, 44% identical at amino acid level).

EXAMPLE 5 PSCYP1 is Only Present in the Genome of the NoscapineProducing P. Somniferum Cultivar GSK NOSCAPINE CVS1

The transcribed region covered by the ESTs contained the complete codingsequence of PSCYP1 (including 5′ and 3′ untranslated regions), which wasused for primer design (Table 1) to amplify the PSCYP1 gene from genomicDNA in a series of overlapping fragments for sequencing. Upon testing asubset of the primer combinations (Table 3) on genomic DNA samples fromall four cultivars it was discovered that the PSCYP1 fragments couldonly be amplified from genomic DNA of the noscapine producing cultivarGSK NOSCAPINE CVS1 but not from genomic DNA of the predominantlymorphine (GSK MORPHINE CVS1, GSK MORPHINE) or thebaine (GSK THEBAINECVS1) producing cultivars (FIG. 5). The PCR amplifications wereperformed on pools of genomic DNA comprising DNA from four individualsper cultivar. This discovery explains why the PSCYP1 is only expressedin the GSK NOSCAPINE CVS1 cultivar and is absent from the transcriptomeof the other three cultivars.

EXAMPLE 6 Assembly of Full Length PSCYP2 cDNA Sequence from ESTs andConfirmation by Sequencing from Genomic DNA

The full length open reading frame of PSCYP2 (FIG. 1 b) was assembledfrom ESTs derived from the 454 sequencing platform using the CAP3sequence assembly programme. The full length cDNA sequence was confirmedby direct amplification of the full length cDNA from GSK NOSCAPINE CVS1genomic DNA.

EXAMPLE 7 PSCYP2 is Exclusively Expressed in the Noscapine ProducingPapaver somniferum Cultivar GSK NOSCAPINE CVS1

FIG. 2 b shows the normalized distribution of ESTs associated with thePSCYP2 consensus sequence across each of the 16 EST libraries preparedfrom two organs (capsules and stems) at two developmental stages (earlyand late harvest) from each of the four poppy cultivars, GSK MORPHINECVS1, GSK MORPHINE CVS2, GSK NOSCAPINE CVS1 and GSK THEBAINE CVS1. ESTscorresponding to PSCYP2 were exclusively found in libraries derived fromthe noscapine producing cultivar GSK NOSCAPINE CVS1 (FIG. 2 b). PSCYP2expression was strongest in stem tissue shortly after flowering.

EXAMPLE 8 PCR-Amplification of PSCYP2 from Genomic DNA of the FourPapaver somniferum Cultivars GSK MORPHINE CVS1, GSK MORPHINE CVS2, GSKNOSCAPINE CVS1 and GSK THEBAINE CVS1

PCR-amplifications of PSCYP2 fragments were performed on genomic DNAfrom the four poppy cultivars GSK MORPHINE CVS1, GSK MORPHINE CVS2, GSKNOSCAPINE CVS1 and GSK THEBAINE CVS1 using the primer combinations shownin Table 2 and 3. FIG. 6 shows the PCR-amplification of PsCYP2 fromgenomic DNA of the four Papaver somniferum cultivars GSK MORPHINE CVS1,GSK MORPHINE CVS2, GSK NOSCAPINE CVS1 and GSK THEBAINE CVS1;

The amplification from genomic DNA yielded the gene sequence shown inFIG. 3 b.

EXAMPLE 9 The Putative Protein Encoded by PSCYP2 Shows Highest SequenceSimilarity to a Cytochrome P450 from Coptis japonica and Thalictrumflavum

The closest homologues to the putative protein encoded by the PSCYP2open reading frame (FIG. 4 b) are cytochrome P450s annotated asstylopine synthase from Argemone mexicana (GenBank accession no.ABR14721, identities: 366/475 (78%)) and from Papaver somniferum(GenBank accession no. ADB89214, identities=373/491 (76%)). The sequencecomparisons were carried out using NCBI's ‘blastp’ algorithm (method:compositional matrix adjust).

EXAMPLE 10 PSCYP2 is Only Present in the Genome of the NoscapineProducing P. Somniferum Cultivar GSK NOSCAPINE CVS1

The transcribed region covered by the ESTs contained the complete codingsequence of PSCYP2 (including 5′ and 3′ untranslated regions), which wasused for primer design (Table 1) to amplify the PSCYP2 gene from genomicDNA in a series of overlapping fragments for sequencing. Upon testing asubset of the primer combinations (Table 3) on genomic DNA samples fromall four cultivars it was discovered that the PSCYP2 fragments couldonly be amplified from genomic DNA of the noscapine producing cultivarGSK NOSCAPINE CVS1 but not from genomic DNA of the predominantlymorphine (GSK MORPHINE CVS1, GSK MORPHINE) or thebaine (GSK THEBAINECVS1) producing cultivars (FIG. 6). The PCR amplifications wereperformed on pools of genomic DNA comprising DNA from four individualsper cultivar. This discovery explains why the PSCYP2 is only expressedin the GSK NOSCAPINE CVS1 cultivar and is absent from the transcriptomeof the other three cultivars.

EXAMPLE 11 Assembly of the Full Length PSCYP3 cDNA Sequence from ESTsand by Sequencing from cDNA and genomic DNA

Two possible full length open reading frames of PSCYP3 (FIGS. 1 c and 1d) were partially assembled from ESTs derived from the 454 sequencingplatform using the CAP3 sequence assembly programme. The ESTs coveredthe 5′ and 3′ area of the sequence with a stretch of 200 bases missing.The missing stretch of bases was obtained by direct amplification andsequencing from cDNA of the GSK NOSCAPINE CVS1. The full lengthsequences were further confirmed by direct amplification and sequencingof PSCYP3 from genomic DNA of the GSK NOSCAPINE CVS1. Two possible ATGstart codons were identified. Since they were in frame and adjacent toeach other the resulting full length open reading frame sequences shownin FIGS. 1 c and 1 d, respectively, differ only by one ATG codon at the5-terminus.

EXAMPLE 12 PSCYP3 is Exclusively Expressed in the Noscapine ProducingPapaver somniferum Cultivar GSK NOSCAPINE CVS1

FIG. 2 c shows the normalized distribution of ESTs associated with thePSCYP3 consensus sequence across each of the 16 EST libraries preparedfrom two organs (capsules and stems) at two developmental stages (earlyand late harvest) from each of the four poppy cultivars, GSK MORPHINECVS1, GSK MORPHINE CVS2, GSK NOSCAPINE CVS1 and GSK THEBAINE CVS1. ESTscorresponding to PSCYP3 were exclusively found in libraries derived fromthe noscapine producing cultivar GSK NOSCAPINE CVS1 (FIG. 2 c). PSCYP3expression was strongest in stem tissue shortly after flowering.

EXAMPLE 13 PCR-Amplification of PSCYP3 from Genomic DNA of the FourPapaver somniferum Cultivars GSK MORPHINE CVS1, GSK MORPHINE CVS2, GSKNOSCAPINE CVS1 and GSK THEBAINE CVS1

PCR-amplifications of PSCYP3 fragments were performed on genomic DNAfrom the four poppy cultivars GSK MORPHINE CVS1, GSK MORPHINE CVS2, GSKNOSCAPINE CVS1 and GSK THEBAINE CVS1 using the primer combinations shownin Table 2 and 3. FIG. 7 shows the PCR-amplification of PSCYP3 fromgenomic DNA of the four Papaver somniferum cultivars GSK MORPHINE CVS1,GSK MORPHINE CVS2, GSK NOSCAPINE CVS1 and GSK THEBAINE CVS1;

The amplification from genomic DNA yielded the gene sequence shown inFIG. 3 c.

EXAMPLE 14 The Putative Protein Encoded by PSCYP3 Shows Highest SequenceSimilarity to Protopine 6-Hydroxylase from Eschscholzia californica

The closest homologue to the putative proteins encoded by the twopossible PSCYP3 open reading frames (FIGS. 1 c and 1 d) is a cytochromeP450s annotated as protopine 6-hydroxylase from Eschscholzia californica(GenBank accession no. BAK20464, identities: 228/522 (44%)) and acytochrome P450 from Coptis japonica (GenBank accession no. BAF98472,identities=230/539 (43%)). The sequence comparisons were carried outusing NCBI's ‘blastp’ algorithm (method: compositional matrix adjust).

EXAMPLE 15 PSCYP3 is Only Present in the Genome of the NoscapineProducing P. Somniferum Cultivar GSK NOSCAPINE CVS1

The transcribed region covered by the ESTs contained the partial codingsequence of PSCYP3 (including 5′ and 3′ untranslated regions), which wasused for primer design (Table 1) to amplify the PSCYP3 gene from genomicDNA in a series of overlapping fragments for sequencing. Upon testing asubset of the primer combinations on genomic DNA samples from all fourcultivars it was discovered that the PSCYP3 fragments could only beamplified from genomic DNA of the noscapine producing cultivar GSKNOSCAPINE CVS1 but not from genomic DNA of the predominantly morphine(GSK MORPHINE CVS1, GSK MORPHINE) or thebaine (GSK THEBAINE CVS1)producing cultivars (FIG. 7). The PCR amplifications were performed onpools of genomic DNA comprising DNA from four individuals per cultivarusing the primer combinations shown in Table 3. This discovery explainswhy the PSCYP3 is only expressed in the GSK NOSCAPINE CVS1 cultivar andis absent from the transcriptome of the other three cultivars.

EXAMPLE 16 Segregation Analysis of PSCYP1 and Noscapine Production in anF2 Mapping Population Derived from a Cross Between GSK NOSCAPINE CVS1and GSK THEBAINE CVS1

Cultivar GSK NOSCAPINE CVS1, which produces noscapine, was crosspollinated with cultivar GSK THEBAINE CVS1 which produces negligibleamounts of noscapine. Resulting F1 plants were grown to maturity and F2seed collected. Two hundred and seventy five F2 individuals from the GSKNOSCAPINE CVS1 and GSK THEBAINE CVS1 10 cross were grown to maturity inthe field. Leaf material was collected from each individual and used forDNA extraction and analysis. Mature capsules were collected from eachindividual for alkaloid extraction and analysis.

FIG. 8 a-c present the results of the F2 mapping population analysis.The PSCYP1, PSCYP2 and PSCYP3 genes are linked and segregate withnoscapine production in the F2 mapping population. The data demonstratethat in the mapping population GSK NOSCAPINE CVS1 levels are present in61 out of 275 individual F2 plants. The PSCYP1, PSCYP2 and PSCYP3 genewere detected in all of the noscapine containing plants thus confirmingthat the PSCYP1, PSCYP2 and PSCYP3 genes and noscapine production arelinked. Furthermore, all plants in which the PSCYP1, PSCYP2 and PSCYP3genes were not detected lacked noscapine (The genotyping assay forPSCYP3 failed on 16 samples as indicated by the failure of the internalpositive control included in the assay; since these samples wereexcluded from the segregation analysis of PSCYP3 with the noscapinetrait). These data are highly statistically relevant and confirm thatthe PSCYP1, PSCYP2 and PSCYP3 genes are required for production of GSKNOSCAPINE CVS1 levels of noscapine.

EXAMPLE 17 Putative Tetrahydrocolumbamine Accumulates in PSCYP2-SilencedPlants

Virus induced gene silencing led to the accumulation of putativetetrahydrocolumbamine in both latex and mature capsules ofPSCYP2-silenced plants but not of PSCYP3-silenced plants, PDS-silencedcontrol plants or uninfected plants of GSK NOSCAPINE CVS1 (FIG. 14). Thedata suggest that PSCYP2 encodes a methylenedioxy-bridge forming enzymewhich converts tetrahydrocolumbamine to canadine thus leading to theformation of the methylenedioxybridge present at C-3a′/C-9a′ of theisoquinoline moiety of noscapine.

EXAMPLE 18 Putative Secoberbines Accumulates in PSCYP3-Silenced Plants

Virus induced gene silencing led to the accumulation of putativesecoberbine alkaloids in both latex and mature capsules ofPSCYP3-silenced plants but not of PSCYP2-silenced plants, PDS-silencedcontrol plants or uninfected plants of GSK NOSCAPINE CVS1 (FIGS. 15 and16). The mass, assigned molecular formula (C21H23NO6) and fragmentationpattern of the putative secoberbine shown to accumulate in FIG. 15 isconsistent with either demethoxyhydroxymacrantaldehyde ordemethoxymacrantoridine. Both of these secoberbines lack a methoxy-groupat the carbon of the isoquinoline moiety which is equivalent to the C-4′of noscapine. The mass, assigned molecular formula (C21H25NO6) andfragmentation pattern of the second compound found to accumulate inPSCYP3-silenced plants (FIG. 16) is consistent with two secoberbines,demethoxynarcotinediol and narcotolinol, respectively. The formercompound lacks the methoxy-group at the carbon equivalent to C-4′ ofnoscapine. Together the data suggest that the protein encoded by PSCYP3hydroxylates the isoquinoline moiety of secoberbines at a positionequivalent to C-4′ of noscapine thus enabling the formation of themethoxy-group present in noscapine at this position by subsequentO-methylation. The respective methoxylated derivatives (methoxylated atthe carbon equivalent to C-4′ of noscapaine) of the putativesecoberbines accumulating in PSCYP3-silenced plants have been found invarious Papaver species producing noscapine (Sariyar and Phillipson(1977) Phytochem. 16: 2009-2013; Sariyar and Shamma (1986) Phytochem.25: 2403-2406, Sariyar (2002) Pure Appl. Chem. 74: 557-574). They havebeen implicated, on structural grounds, in the biosynthetic conversionof protoberberines into phthalideisoquinolines such as noscapine(Sariyar and Shamma (1986) Phytochem. 25: 2403-2406, Sariyar andPhillipson (1977) Phytochem. 16: 2009-2013).

1. An isolated nucleic acid molecule that encodes a cytochrome P450polypeptide wherein said nucleic acid molecule comprises or consists ofa nucleotide sequence selected from the group consisting of: i) anucleotide sequence as represented by the sequence in SEQ ID NO: 1, 2,3, 4, 5, 6 or 7; ii) a nucleotide sequence wherein said sequence isdegenerate as a result of the genetic code to the nucleotide sequencedefined in (i); iii) a nucleic acid molecule the complementary strand ofwhich hybridizes under stringent hybridization conditions to thesequence in SEQ ID NO: 1, 2, 3, 4, 5, 6 or 7 wherein said nucleic acidmolecule encodes a cytochrome P450 polypeptide; iv) a nucleotidesequence that encodes a polypeptide comprising an amino acid sequence asrepresented in SEQ ID NO: 8, 9, or 10; and v) a nucleotide sequence thatencodes a polypeptide comprising an amino acid sequence wherein saidamino acid sequence is modified by addition deletion or substitution ofat least one amino acid residue as represented in iv) above and whichhas retained or enhanced cytochrome P450 activity.
 2. The isolatednucleic acid molecule according to claim 1, wherein said nucleic acidmolecule comprises or consists of a nucleotide sequence as representedin SEQ ID NO: 1, 2, 3, 4, 5, 6 or
 7. 3. An isolated polypeptide selectedfrom the group consisting of: i) a polypeptide comprising or consistingof an amino acid sequence as represented in SEQ ID NO: 8, 9, or 10; andii) a modified polypeptide comprising or consisting of a modified aminoacid sequence wherein said polypeptide is modified by addition deletionor substitution of at least one amino acid residue of the sequencepresented in SEQ ID NO: 8, 9, OR 10 and which has retained or enhancedcytochrome P450 activity.
 4. The isolated polypeptide according to claim3 wherein the variant polypeptides have at least 43% identity with theamino acid sequence represented in SEQ ID NO: 8, 9, or 10 and whichretains or has enhanced cytochrome P450 activity.
 5. A vector comprisinga nucleic acid molecule encoding a cytochrome P450 polypeptide accordingto claim 1 wherein said nucleic acid molecule is operably linked to anucleic acid molecule comprising a promoter sequence.
 6. The vectoraccording to claim 5 wherein said nucleic acid sequence comprising apromoter confers constitutive expression on said cytochrome P450polypeptide.
 7. A transgenic cell transformed or transfected with thenucleic acid molecule of claim
 1. 8. The transgenic cell according toclaim 7 wherein said cell is a plant cell.
 9. The transgenic cellaccording to claim 8 wherein said plant cell is from the familyPapaveraceae.
 10. The transgenic cell according to claim 9 wherein saidplant cell is a Papaver somniferum cell.
 11. A plant comprising theplant cell of claim
 8. 12. The plant according to claim 11 wherein saidplant is from the family Papaveraceae.
 13. The plant according to claim12 wherein said plant is Papaver somniferum.
 14. The transgenic cellaccording to claim 7 wherein said cell is a microbial cell.
 15. Thetransgenic cell of claim 7 wherein said cell is adapted such that thenucleic acid molecule encoding the cytochrome P450 is over-expressedwhen compared to a non-transgenic cell or plant of the same species. 16.A nucleic acid molecule comprising a transcription cassette wherein saidcassette includes a nucleotide sequence designed with reference to SEQID NO: 1, 2, 3, 4, 5, 6 or 7 and is adapted for expression by provisionof at least one promoter operably linked to said nucleotide sequencesuch that both sense and antisense molecules are transcribed from saidcassette.
 17. The nucleic acid molecule according to claim 16 whereinsaid cassette is adapted such that both sense and antisense ribonucleicacid molecules are transcribed from said cassette wherein said sense andantisense nucleic acid molecules are adapted to anneal over at leastpart or all of their length to form a siRNA or shRNA.
 18. The nucleicacid molecule according to claim 17 wherein said cassette is providedwith at least two promoters adapted to transcribe both sense andantisense strands of said ribonucleic acid molecule.
 19. The nucleicacid molecule according to claim 16, wherein said cassette comprises anucleic acid molecule wherein said molecule comprises a first partlinked to a second part wherein said first and second parts arecomplementary over at least part of their sequence and further whereintranscription of said nucleic acid molecule produces a ribonucleic acidmolecule which forms a double stranded region by complementary basepairing of said first and second parts thereby forming an shRNA.
 20. Thenucleic acid molecule according to claim 16, wherein said nucleic acidmolecule is part of a vector adapted for expression in a plant cell. 21.A plant cell transfected with the nucleic acid molecule claim 16,wherein said cell has reduced expression of said cytochrome P450polypeptide.
 22. A process for the modification of an opiate alkaloidcomprising: i) providing the transgenic plant cell according to claim21; ii) cultivating said plant cell to produce a transgenic plant; andoptionally iii) harvesting said transgenic plant, or part thereof. 23.The process according to claim 22 wherein said harvested plant part isdried straw and said opiate alkaloid is extracted.
 24. A process for themodification of an opiate alkaloid comprising: i) providing thetransgenic microbial cell according to claim 14 that expresses acytochrome P450 in culture with at least one opiate alkaloid; ii)cultivating the microbial cell under conditions that modify one or moreopiate alkaloids; and optionally iii) isolating said modified alkaloidfrom the microbial cell or cell culture.
 25. The process according toclaim 24 wherein said microbial cell is a bacterial cell or fungal/yeastcell.
 26. (canceled)
 27. A method to determine the presence or absenceof a gene that encodes a polypeptide with cytochrome P450 activity in aPapaveraceae variety comprising: i) obtaining a sample from aPapaveraceae plant; ii) extracting genomic DNA from the plant; and iii)analyzing the genomic DNA for the presence of a gene comprising orconsisting of a nucleotide sequence as represented in SEQ ID NO: 2, 4,5, 6, or
 7. 28. The use of a gene encoded by a nucleic acid molecule asrepresented by the nucleic acid sequence in SEQ ID NO: 5, 6, or 7; or anucleic acid molecule that hybridizes under stringent hybridizationconditions to the nucleotide sequence in SEQ ID NO: 5, 6, or 7 andencodes a polypeptide with cytochrome P450 activity as a means toidentify a locus wherein said locus is associated with alteredexpression or activity of said cytochrome P450.
 29. A method to producea Papaveraceae plant variety that has altered expression of a cytochromeP450 polypeptide comprising: i) mutagenizing wild-type seed from a plantthat does express said cytochrome P450 polypeptide; ii) cultivating theseed in i) to produce first and subsequent generations of plants; iii)obtaining seed from the first generation plant and subsequentgenerations of plants; iv) determining if the seed from said first andsubsequent generations of plants has altered nucleotide sequence and/oraltered expression of said cytochrome P450 polypeptide; v) obtaining asample and analyzing the nucleic acid sequence of a nucleic acidmolecule selected from the group consisting of: a) a nucleic acidmolecule comprising a nucleotide sequence as represented in SEQ ID NO:5, 6, or 7; and b) a nucleic acid molecule that hybridizes to thenucleic acid molecule in a) under stringent hybridization conditions andthat encodes a polypeptide with cytochrome P450 polypeptide activity;and optionally vi) comparing the nucleotide sequence of the nucleic acidmolecule in said sample to a nucleotide sequence of a nucleic acidmolecule of the original wild-type plant.
 30. The method according toclaim 29 wherein said nucleic acid molecule is analyzed by a methodcomprising: i) extracting nucleic acid from said mutated plants; ii)amplifying a part of said nucleic acid molecule by a polymerase chainreaction; iii) forming a preparation comprising the amplified nucleicacid and nucleic acid extracted from wild-type seed to form heteroduplexnucleic acid; iv) incubating said preparation with a single strandednuclease that cuts at a region of heteroduplex nucleic acid to identifythe mismatch in said heteroduplex; and iv) determining the site of themismatch in said nucleic acid heteroduplex.
 31. The method according toclaim 30 wherein said Papaveraceae plant variety has enhanced cytochromeP450 polypeptide expression and/or activity.
 32. A plant obtained by themethod according to claim
 29. 33. A plant comprising a viral vector thatincludes all or part of a gene comprising the nucleic acid moleculeaccording to claim
 1. 34. The plant according to claim 33 wherein saidgene is encoded by a nucleic acid molecule comprising a nucleic acidsequence selected from the group consisting of: i) a nucleic acidmolecule comprising or consisting of a nucleotide sequence asrepresented in SEQ ID NO: 1, 2, 3, or 4; ii) a nucleic acid moleculecomprising a nucleotide sequence that hybridizes under stringenthybridization conditions to a nucleic acid molecule in (i) and whichencodes a cytochrome p450 polypeptide; and iii) a nucleic acid moleculethat encodes a variant polypeptide that varies from a polypeptidecomprising the amino acid sequence as represented in SEQ ID NO: 8, 9, 10or
 11. 35.-38. (canceled)
 39. The plant according to claim 34 whereinsaid nucleic acid molecule consists of a nucleotide sequence asrepresented in SEQ ID NO: 13 or
 14. 40. (canceled)
 41. A viral vectorcomprising all or part of the nucleic acid molecule according toclaim
 1. 42.-43. (canceled)
 44. A method of gene silencing in a plant,comprising: introducing the viral vector of claim 41 into the plant,thereby inducing gene silencing.
 45. The method of claim 44, wherein theplant is from the family Papaveraceae.